Basic oxygen furnace construction



United States Patent 3,370,840 BASIC OXYGEN FURNACE CONSTRUCTION Michael E. Cole, Pittsburgh, Pa., assiguor to Hal-bison- Walker Refractories Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed July 30, 1965, Ser. No. 476,055 3 Claims. (Cl. 266-43) ABSTRACT OF THE DISCLOSURE In the oxygen steelmaking process, which has been variously designated as the LD process, oxygen Bessemer process, and the oxygen converter process, the furnace structure fundamentally consists of a metal shell having a refractory lining disposed therein. The lining forv oxygen steel furnaces consists of an inner or working-lining and an exterior or tank lining, sometimes with an intermediate brick or rammed lining. The vessel is generally composed of three major zones, these three zones being the bottom zone, the barrel zone, and the cone section zone.-The'bottom zone is generally dish-shaped and of upwardly opening concave configuration. The-barrel zone extends from the dish-shaped bottom upwardly to the cone section zone. The cone section zone is of downwardly opening truncated cross-section configuration. Usually, brick in all three zones of the working lining are laid so that the end surface of smallest area is exposed to the interior ofsaid vessel: Similarly, the brick in the tank lining are laid so that an end surface is adjacent the metal shell.

The area in the vessel where the barrel zone brick meet the bottom zone brick is referred to as the knuckle aea. At the point of meeting, the face surfaces of the brick in the bottom zone are inclined from the vertical axis of the vessel; whereas, the face surfaces of the brick in the barrel zone are substantially horizontal. Thus, in this area, the interior end surfaces of the brick in the barrel zone are closely adjacent the brick in the bottom zone, while the opposite end surfaces thereof are widely separated. Stated another way, from the point interior of said, vessel where the brick in the barrel zone and bottom zone meet, they diverge toward the tank lining. I

The knuckle area between the brick in the bottom and barrel zones has become a major point of weakness to the structural integrity of the vessel. Various types of refractory shapes have been proposed to fill in the void between these divergent brick at the working lining to provide re.- sistance to erosion, especially during pouring of the molten metal, and to the stresses and strains encountered in vessel operation. These stresses and strains are caused by the physical movement and manipulation of thevessel or fur- 3,370,840 Patented Feb. 27, 1968 ice nace itself during the steelmaking operation, i.e. wide and cyclic variation in temperature, due to successive charging and tapping of heats of metal from the vessel etc.

Accordingly, it is among the objects of the present invention to provide an improved knuckle area construction at the working lining for oxygen steelmaking vessels.

Other objects of the invention will become apparent hereinafter.

In order to more fully understand the nature and scope of the invention, reference should be had to the following detailed description and drawings in which:

FIG. 1 is a schematic elevation view, partly broken, of a typical oxygen converter vessel;

FIGS. 2 and 3 are partial sections of prior art constructions in the knuckle area of oxygen steelmaking vessels; and

FIG. 4 is a partial section of knuckle area construction in an oxygen converter vessel according to the present invention.

Briefly, in accordance with the present invention, the improved construction in the knuckle area of a basic oxygen furnace working lining consists of a plurality of refractory brick having substantially parallel skew end surfaces and substantially'parallel face surfaces. The brick are disposed in such a manner that their skew end surfaces are parallel to the face surfaces of the brick in the barrel zone, and their face surfaces are parallel to the face sur faces of the inclined brick in the bottom zone. This arrangement allows surface to surface abutment of brick in the knuckle area.

Referring to FIG. 1, there is shown a typical basic oxygen furnace 10 consisting of an outer metal shell 12, a shell protective brick lining 14 in contact with the inside surface of the shell and a brick working lining 16. The vessel is constructed of three major zones, the bottom zone 18, the barrel zone 20, and the cone section zone 22. The

1 extends from the knuckle area upwardly to the cone section zone. The cone section zone, having the taphole 26, etxends upwardly and terminates in the form of a mouth 28 at the top of the vessel. The cone section zone is of downwardly opening truncated cross sectional configuration. The typical construction of FIG. 1 shows the knckle area .24 to contain key-type refractory brick 30 in the shell protective or tank lining 14 conforming to the contours of the shell. The brick 23 and 29 in the working lining are contoured toward the knuckle 24 until the interior ends almost meet, thus leaving a void 34 between the divergent face surfaces. This void is filled in with monolithic refractory material 36.

Since an unburned monolithic refractory material has substantially less resistance to erosion and stress than does dense, burned basic refractory brick, in the knuckle area of the vessel, a great deal of difiiculties and downtime were encountered with such vessels.

Prior workers sought to eliminate the monolithic refractory material entirely from the working lining of the vessel by employing sectioned refractory brick between the dishthe contour of the bottom zone. FIG. 2 shows the results of this endeavor. The brick 40 in the bottom zone were continued through the knuckle area 24 by cutting the interior surfaces thereof to fit roughly against the terminal face surfaces 42 of the brick in the straight barrel zone. Another approach, shown in FIG. 3 is the extension of brick 44 in the barrel zone downwardly by cutting the exterior end surfaces thereof to provide a relatively rough fitting of brick in the void created by the terminal brick in the barrel zone and bottom zone respectively. While both of the above (FIGS. 2 and 3) knuckle area constructions were found to be superior to the monolithic knuckle area construction, their resistance to erosion and stresses was'stillconsidered inadequate, owing to a relatively loose brick to brick joint, i.e. one in the inclined plane and the other in the horizontal plane.

FIG. 4 shows a knuckle area construction according to the present invention. The brick employed to fabricate the knuckle area contain substantially parallel skew end faces 46 and substantially parallel face surfaces 48. The brick in cross section appear as a parallelogram configuration. The brick are arranged in the knuckle area in contiguous relationship, so that certain of the brick 50 have a skew end surface in contiguous contact with the face surface of the terminalbrick in the barrel zone. Other of the brick 52 are disposed such that a face sur face is contiguous with a face surface of the inclined brick in the bottom zone. One of the knuckle area brick 54, in each course, has a skew end face contiguous with a face surface of a terminal brick in the barrel zone and a face surface contiguous with a face surface of a terminal inclined brick in the bottom zone. Other brick 56 of similar configuration are fitted between the terminal brick face surface contacting skew end brick, in close abutment to provide a structurally integral knuckle area. Theremaining voids between the skew end brick and the tank lining may be filled with monolithic refractory material 58.

Another way of describing the invention is as follows: The knuckle area of a basic oxygen furnace is an annular space which, in cross section, defines a sector of a circle (i.e. it is pie shaped), in which the chord of the'sector is bounded by the tank lining and the sides of the sector by the bottom brick of the barrel zone and the top brick of the bottom zone. A plurality of contiguously abutting refractory brick, of parallelogram cross-sectional configuration substantially fills said sector from contiguous said bottom brick of the barrel zone to contiguous the top brick of the bottom zone entirely about said annular space.

In practice, the working lining is laid as follows: The brick in the bottom zone are disposed in substantially the center of the zone for each course on the tank lining so that the face surfaces of the bottom brick are in alignment with the vertical axis of the vessel. The courses are then continued on the tank lining toward the curvature in the shell until the knuckle area is reached. At this point, the face surfaces of the brick are inclined from the vertical axis of the vessel. A plurality of brick having substantially parallel skew end surfaces and face surfaces, are disposed in abutment with the terminal brick in the bottom zone so that the face surfaces of all of said'knuckle brick are parallel to the face surfaces of the terminal inclined brick. As a result, the skew end surfaces of all the knuckle area brick are in alignment with the horizontal axis of the vessel. Then the horizontal brick of the barrel zone are laid so that the face surfaces of the first brick course are contiguous with the skew end sur-' face of the knuckle area brick. The remainder of the barrel zone lining and the cone section zone lining is con tinued by stacking brick on brick.

Accordingly, a highly erosion and stress resistant structure is obtained in the knuckle area om'ng to relatively tight brick to brick joints in. the horizontal plane and the inclined plane which eifecti ely alleviates the problems hllOfOI :efiCOufiferedT "M Y It should be appreciated, of course, that the size and quantity of brick in the knuckle area will vary depending on the size and shape of the oxygen steelmaking vessel.

-It is intended that the foregoing description and drawings be construed as illustrative and not in limitation of the invention.

Having thus described the invention in detail and with sufficient particularity as to enable those skilled in the.

art to practice it, what is desired to have protected by Letters Patent is set forth in the following claims.

1 claim:

1. In an oxygen converter vessel comprising a metal shell having a mouth at its top, a shell protective lining in contact with the inside surface thereof and a working lining, said vessel constructed'of three major zones, the bottom zone, the barrel zone, and the cone section zone, the three zones containing refractory brick having generally face, side and end surfaces, an end surface of each brick in these zones in the working lining being exposed to the interior of said vessel, the bottom zone being generally dish-shaped and of upwardly opening concave configuration, the brick in said zone terminating in a knuckle area with their face surfaces inclined from the vertical axis of the vessel, the barrel zone extendingfrom the knuckle area upwardly to the cone section zone, the cone section zone being of downwardly opening truncated cross section configuration, the improvement comprising-a plurality of refractory brick in the knuckle area, at the working lining, having substantially parallel skew end surfaces and substantially parallel facesurfaces, the brick being disposed such that their skew end surfaces are parallel to the face surfaces of the brick in the barrel zone and their face surfaces are parallel to the face surfaces of the inclined brick in the bottom zone.

2. In an oxygen converter vessel comprising a metal shell having a mouth at its top, a shell protective lining in contact with the inside surface thereof and a working lining, said vessel constructed of three major zones, the bottom zone, the barrel zone, and the cone section zone, the three zones containing refractory brick having generally face, side and end surfaces, an end surface of each brick in these zones in the working liningbeing exposed to the interior of said vessel, the bottom zone being generally dish-shaped and of upwardly opening concave configuration, the brick in said zone terminating in a knuckle area with their face surfaces inclined from the vertical axis of the vessel, the barrel zone extending from the knuckle area upwardly to the cone section zone, the cone section zone being of downwardly opening truncated cross section configuration, the improvement comprising a plurality of refractory brick in the knuckle area, at the working lining having substantially parallel skew end surfaces and substantially parallel face surfaces, certain of said brick being disposed such that a skew end surface is contiguous with a face surface of the brick in the barrel zone, other of said brick being disposed such that a face surface iscontiguous with a face surface of the inclined brick in the bottom zone, one of said brick having a skew end surface contiguous with'a face surface of a brick in the barrel zone and a face surface contiguous with a face surface of an inclined brick in the bottom zone, all of said brick being contiguous with an adjacent brick.

3. In an oxygen converter vessel comprising a 'metal shell having a mouth at its .top, a shell protectivelini'ng in contact with the'inside surface thereof and a working lining, said vessel constructed of three major zones, the

- bottom zone, the barrel zone, and the cone section-zone,

surfaces inclined from the vertical axis of the vessel, the barrel zone extending from the knuckle area upwardly to the cone section zone, the cone section zone being of downwardly opening truncated cross section configuration, the improvement comprising a plurality of refractory brick in the knuckle area, at the working lining having substantially parallel skew end surfaces and substantially parallel face surfaces, the brick being disposed in such a manner to provide continuous skew end surface to surface abutment with the inclined brick in the bottom zone, all of said brick in the knuckle area being contiguous with an adjacent brick.

References Cited UNITED STATES PATENTS 1,944,278 1/1934 Schultz 26643 X 2,829,877 4/1958 Davis 26643 X 3,281,137 10/ 1966 Alper et al. 26643 FOREIGN PATENTS 637,604 l()/ 1936 Germany.

10 I. SPENCER OVERHOLSER, Primary Examiner.

E. MAR, Assistant Examiner. 

